Itoh H, Minakuchi C, Hase K
Department of Anesthesiology, Tokyo Saiseikai Central Hospital.
Masui. 1991 Aug;40(8):1198-203.
The inhibition of cardiac muscle contractility with bupivacaine was about tenfold of that with lidocaine, namely the ID50 values of bupivacaine and lidocaine were 10(-6) M and 10(-5) M, respectively. With bupivacaine above 3 x 10(-6) M, the contraction was diminished completely. In the medium of a high calcium concentration (Ca2+:5.0 mM), the effect of lidocaine (10(-5) M) was antagonized markedly, but that of bupivacaine was not antagonized so much. These results suggest that they might have some different mechanisms in respect to the inhibition of the contractility, for instance bupivacaine affecting mainly sarcoplasmic reticulum and lidocaine affecting mainly sarcolemma.
布比卡因对心肌收缩力的抑制作用约为利多卡因的10倍，即布比卡因和利多卡因的半数抑制浓度（ID50）分别为10^(-6)M和10^(-5)M。当布比卡因浓度高于3×10^(-6)M时，收缩作用完全减弱。在高钙浓度（Ca2+：5.0 mM）的培养基中，利多卡因（10^(-5)M）的作用受到显著拮抗，但布比卡因的作用未受到如此大的拮抗。这些结果表明，它们在抑制收缩力方面可能有一些不同的机制，例如布比卡因主要影响肌浆网，而利多卡因主要影响肌膜。
